Welcome to the Piano World Piano ForumsOver 2.5 million posts about pianos, digital pianos, and all types of keyboard instruments
Join the World's Largest Community of Piano Lovers
(it's free)
It's Fun to Play the Piano ... Please Pass It On!

The floor is on a gimbal which creates a slight rocking to the movement of the base. The weights on the metronomes will affect the center of gravity of the platform, and its travel arc speed, and ultimately come into synchronis movement. This would not happen on a fixed, level surface.

The floor is on a gimbal which creates a slight rocking to the movement of the base. The weights on the metronomes will affect the center of gravity of the platform, and its travel arc speed, and ultimately come into synchronis movement. This would not happen on a fixed, level surface.

Well, we've now gone from physics to clockmaking. It would depend on the escapement energy in the clock mechanism in relation to inertia/mass. That is, the mechanical energy stored within the spring to be released in a repetitive sequence. The synchronis movement would continue until the springs/escapement could no longer affect the "whole." Once you have less than 50% of the metronomes in action, they would start to go out of synch as they would no longer contain sufficient stored energy to affect the "dead weight" of the stopped ones through the movement of the base.

I would think that they pretty quickly run out of sync, since each one is a somewhat crudely constructed mechanical device, and the inherent tension in the spring that drives each will be slightly different.

I would also be very surprised if I were told that a minimal number of mechanical metronomes from the same manufacturer would beat at exactly the same tempo when set at the same tempo on a stable surface. I presume that mechanical metronomes are not manufactured to very high standards, that there are probably infinite variations in the quality of assembly and even in such things as the mass of the weight and the precise positions of the tempo markers on the bar.